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Related papers: Dephasing-enabled triplet Andreev conductance

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Resonant tunneling through identical potential barriers is a textbook problem in quantum mechanics. Its solution yields total transparency (100% tunneling) at discrete energies. This dramatic phenomenon results from coherent interference…

Mesoscale and Nanoscale Physics · Physics 2015-06-25 Daniel Rohrlich , Oren Zarchin , Moty Heiblum , Diana Mahalu , Vladimir Umansky

We theoretically study the dephasing of an Andreev spin qubit (ASQ) due to electric and magnetic noise. Using a tight-binding model, we calculate the Andreev states formed in a Josephson junction where the link is a semiconductor with…

Mesoscale and Nanoscale Physics · Physics 2024-03-04 Silas Hoffman , Max Hays , Kyle Serniak , Thomas Hazard , Charles Tahan

We show that singlet-triplet superpositions of two-electron spin states in a double quantum dot undergo a phonon-induced pure dephasing which relies only on the tunnel coupling between the dots and on the Pauli exclusion principle. As such,…

Mesoscale and Nanoscale Physics · Physics 2010-09-15 Katarzyna Roszak , Pawel Machnikowski

We have studied the dephasing of a superconducting flux-qubit coupled to a DC-SQUID based oscillator. By varying the bias conditions of both circuits we were able to tune their effective coupling strength. This allowed us to measure the…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 P. Bertet , I. Chiorescu , G. Burkard , K. Semba , C. J. P. M. Harmans , D. P. DiVincenzo , J. E. Mooij

We investigate a dephasing mechanism in a quantum dot capacitively coupled to a quantum point contact. We use a model which was proposed to explain the 0.7 structure in point contacts, based on the presence of a quasi-bound state in a point…

Mesoscale and Nanoscale Physics · Physics 2009-11-13 Tomosuke Aono

We consider two one-dimensional quantum $XX$ magnets linked by a periodically driven quantum point contact (QPC). If magnets are initially polarized in opposite directions, one expects that a spin current through the QPC will establish. It…

Mesoscale and Nanoscale Physics · Physics 2024-10-02 Igor Ermakov , Oleg Lychkovskiy

Random fluctuations caused by environmental noise can lead to decoherence in quantum systems. Exploring and controlling such dissipative processes is both fundamentally intriguing and essential for harnessing quantum systems to gain…

We apply the scattering matrix approach to the triplet proximity effect in superconductor-half metal structures. We find that for junctions that do not mix different orbital modes, the zero bias Andreev conductance vanishes, while the zero…

Superconductivity · Physics 2009-01-27 B. Béri , J. N. Kupferschmidt , C. W. J. Beenakker , P. W. Brouwer

The zero-temperature magnetic field-dependent conductance of electrons through a one-dimensional non-interacting tight-binding chain with an interacting {\it side} dot is reviewed and analized further. When the number of electrons in the…

Strongly Correlated Electrons · Physics 2007-05-23 M. E. Torio , K. Hallberg , C. Proetto

In the "ballistic" regime, the transport across a normal metal (N)/superconductor (S) point-contact is dominated by a quantum process called Andreev reflection. Andreev reflection causes an enhancement of the conductance below the…

Superconductivity · Physics 2021-10-04 Ritesh Kumar , Goutam Sheet

Andreev reflection between a normal metal and a superconductor whose order parameter exhibits quantum phase fluctuations is examined. The approach chosen is non perturbative in the tunneling Hamiltonian and enables to probe the whole range…

Superconductivity · Physics 2009-11-07 P. Devillard , R. Guyon , T. Martin , I. Safi , B. K. Chakraverty

Conductance signatures that signal the presence of Majorana zero modes in a three terminal nanowire-topological superconductor hybrid system are analyzed in detail, in both the clean nanowire limit and in the presence of non-coherent…

Mesoscale and Nanoscale Physics · Physics 2021-08-11 Chaitrali Duse , Praveen Sriram , Kaveh Gharavi , Jonathan Baugh , Bhaskaran Muralidharan

Recent works have predicted materials featuring bands with a large spin-splitting distinct from ferromagnetic and relativistically spin-orbit coupled systems. Materials displaying this property are known as altermagnets and feature a…

Superconductivity · Physics 2023-08-15 Chi Sun , Arne Brataas , Jacob Linder

Kondo correlation in a spin polarized quantum dot (QD) results from the dynamical formation of a spin singlet between the dot's net spin and a Kondo cloud of electrons in the leads, leading to enhanced coherent transport through the QD. We…

Mesoscale and Nanoscale Physics · Physics 2009-11-10 M. Avinun-Kalish , M. Heiblum , A. Silva , D. Mahalu , V. Umansky

A study is presented concerning the influence of flicker noise in the junction transparency on coherent transport in Andreev states. The amount of dephasing is estimated for a microwave-activated quantum interferometer. Possibilities of…

Superconductivity · Physics 2009-10-31 N. I. Lundin , Y. M. Galperin

Time-reversal invariant superconductors having nodes of vanishing excitation gap support zero-energy boundary states with topological protection. Existing expressions for the topological invariant are given in terms of the Hamiltonian of an…

Superconductivity · Physics 2012-11-29 J. P. Dahlhaus , M. Gibertini , C. W. J. Beenakker

We develop a theory of charge transport along the quantum Hall edge proximitized by a "dirty" superconductor. Disorder randomizes the Andreev reflection rendering the conductance of a proximitized segment a stochastic quantity with zero…

Mesoscale and Nanoscale Physics · Physics 2023-05-17 Vladislav D. Kurilovich , Zachary M. Raines , Leonid I. Glazman

We study a strongly interacting quantum dot connected to a normal and to a superconducting lead. By means of the slave-boson technique we investigate the low temperature regime and discuss electrical transport through the dot. We find that…

Mesoscale and Nanoscale Physics · Physics 2009-10-31 P. Schwab , R. Raimondi

The dephasing rate of an electron level in a quantum dot, placed next to a fluctuating edge current in the fractional quantum Hall effect, is considered. Using perturbation theory, we first show that this rate has an anomalous dependence on…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 T. K. T Nguyen , A. Crepieux , T. Jonckheere , A. V. Nguyen , Y. Levinson , T. Martin

We report a systematic experimental study of mesoscopic conductance fluctuations in superconductor/normal/superconductor (SNS) devices Nb/InAs-nanowire/Nb. These fluctuations far exceed their value in the normal state and strongly depend on…

Mesoscale and Nanoscale Physics · Physics 2009-12-18 T. S. Jespersen , M. L. Polianski , C. B. Soerensen , K. Flensberg , J. Nygaard